I use a venturi diffuser with DIY CO2. The powerhead is on the same timer as the lights but the CO2 injection can't be turned off like pressurized CO2. Its been 1 1/2 hours since lights and powerhead went off but the pH has not moved from the 6.4 range. Am I too impatient with degassing or is CO2 still dissolving into my water at a rather fast rate. The CO2 is coming out of the burp tube right now since the diffuser container has filled up with a nice pocket of gas. The only source of surface disturbance in my 29 gallon is my penguin biowheel 200 filter. Should I run an airstone after lights out to aid in degassing the water or will it naturally degas on its own at night without subjecting the fish to 24/7 high CO2 levels.